Electronic device manufacturers strive to produce a rich interface for users. Conventional devices use visual and auditory cues to provide feedback to a user. In some interface devices, kinesthetic feedback (such as active and resistive force feedback) and/or tactile feedback (such as vibration, texture, and heat) is also provided to the user, more generally known collectively as “haptic feedback” or “haptic effects.” Haptic feedback can provide cues that enhance and simplify the user interface. Specifically, vibration effects, or vibrotactile haptic effects, may be useful in providing cues to users of electronic devices to alert the user to specific events, or provide realistic feedback to create greater sensory immersion within a simulated or virtual environment.
Haptic feedback has also been increasingly incorporated in portable electronic devices, referred to as “handheld devices” or “mobile terminal devices,” such as cellular telephones, personal digital assistants (“PDA”s), smart phones, and portable gaming devices. For example, some portable gaming applications are capable of vibrating in a manner similar to control devices (e.g., joysticks, etc.) used with larger-scale gaming systems that are configured to provide haptic feedback. Additionally, devices such as cellular telephones and PDAs are capable of providing various alerts to users by way of vibrations. For example, a cellular telephone can alert a user to an incoming telephone call by vibrating. Similarly, a PDA can alert a user to a scheduled calendar item or provide a user with a reminder for a “to do” list item or calendar appointment.
Many mobile terminal devices, in addition to handling voice telephone calls, allow for messaging between devices. Short Message Service (“SMS”), also known as text messaging, is a popular communication method that enables the exchange of short text messages between mobile terminal devices via the Short Message Service Centre (“SMSC”) in a mobile network. Other known messaging methods for mobile terminal devices include Multimedia Messaging Service (“MMS”), Mobile Instant Messaging, and Mobile Email. MMS is a store and forward messaging service that allows mobile subscribers to exchange multimedia messages with other mobile subscribers. As such, it can be seen as an evolution of SMS, with MMS supporting the transmission of additional media types, including text, picture, audio, video, or a combination of all four. Instant Messaging (“IM”) is an Internet Protocol (“IP”) based application that can provide real-time written communication between users of a computer. Mobile Instant Messaging is the ability to engage in Instant Messaging services from a mobile handset. Mobile IM allows users to address messages to other users using an alias (or user name) and address book, and incorporates the concept of presence, enabling the sender to know when his/her “buddies” are available. Mobile Email is the ability to send and receive e-mail over wireless devices.
Haptic feedback can be used to provide additional information that may not be apparent in the text of the message to the recipient of a message. For example, a text message sent to another user at a mobile terminal device may not include information indicating how strong the user feels about the topic expressed or other message subtext. Users can try to express this subtext using well-known icons or symbols known as “emoticons,” which are culturally dependent iconic representations of emotions or messages. For example, a “smiley” emoticon to indicate a humorous message may be expressed as a colon and right parenthesis mark, “:)”, which resembles a face smiling when viewed from the side, or may also be expressed as a combination of parenthesis, carets, and an underline “(^_^)”. Variations of the smiley emoticon can express a variety of other emotions. However, emoticons and symbols are limited in the complexity of the messages they can convey.